Mineralogical characteristics of nickel laterite in the Buper area, Jayapura, Papua, Indonesia

The Buper area has ultramafic rock types which mostly consist of harzburgite, serpentinite, pyroxenite and dunnite. This study aimed to determined minerals chemical composition, minerals phase structure and morphological surface of nickel laterite in Buper area, Jayapura, Papua, Indonesia. The study applied experimental method by extracting samples at the research site and conducting samples with X-ray fluorescence (XRF), X-ray diffraction (XRD) and Scanning Electron (SEM). The result showed that the percentage of nickel (Ni) element in the topsoil layer was 0.6 %, in the red limonite layer by 0.695 %, in the yellow limonite layer by 1.81 % and in the saprolite layer by 19.85 %. The XRD spectrums showed that the topsoil and the red limonite zones were dominated by the goetite compound (Fe H O2), then quartz (SiO2), and Neodymium Nickel (III) Oxide (Nd Ni O3), while the yellow limonite zone was dominated by quartz compounds (SiO2), then the goetite compound (Fe H O2) and then Neodymium Nickel (III) Oxide (Nd Ni O3) compound. In the saprolite zone, the highest peak of the XRD spectrum is Neupoite compound [(Ni, Mg)3 (Si2O5) (O H4)], then Quartz (SiO2) and then goetite (Fe HO2). Samples of nickel laterite taken from Buper Area, Jayapura come in brown in topsoil, reddish brown in red limonite zone, yellowish brown in the yellow limonite zone and graywhite on the saprolite zone.